Perhaps Square Enix decided to collaborate with Team Ninja because of Dead Fantasy, that's what I'm guessing. I liked the crossover, but I think a crossover with Soul Calibur would have made more sense, because Soul Calibur has weapons and some magic, although not as much magic as Street Fighter, Guilty Gear, or BlazBlue. Dead or Alive has very little magic, if any magic at all, and Dissidia is not a traditional fighting game.

Also, Team Ninja has stated that there will be no Dead or Alive characters in the new Dissidia.